Impulse turbine



L.. F. MOODY IMPULSE TURBINE May 21, 1929.

Original Filed Feb. l5 1921 yPatented May 21d, 1929.

UNITED STATES PATENT- oFFIcE.-

LEWIS FERRY MOODY, OF PHILADELPHIA, PENNSYLVANIA.

nurULsn TURBINE.

Original application filed February 15, 1921, Serial No. 445,067.Divided and ythis application led November 13, 1925. Serial No. 68,897.

This invention relates to impulse turbines and particularly to turbineshaving a high specilic speed.v The object of kthe invention isy toprovide an impulse turbinev of the radial flow type in which the jet iscontinuous around the ilow to the nozzle.

the periphery of the runner so as to simultaneously act on all thebuckets at once and in similar' manner.

which Fig. 1 is a vertical sectional view of` one embodiment of theinvention 1n an outward How turbine.

Fig, 2 is a horizontal sectional view onV line 2-2 of Fig. 1, and 1 Fig.3 is a similar view of a modication. In the turbine shown in Figs. 1 and2'the iow enters through the intake 48 'passes upward an'd outwardthrough the inclined stay and guide vanes 49 land out ofthe nozzle '50radially with an inclination' or whirl .due to the inclination of theguides 49 and the upper part 51 of the intake casing supported on vanes49 is conically curved to smoothly guide The runner r of thismodificationcarries the outward low buckets 5 receiving the jet y" attheir inner edges anddischarging it at their outer edges. The

, runner is formed with an upper'bucket ring 53 and a lower bucket ring54 between which the blades or vanes b extend and are preferablyinclined to the radial as shown in-Fig. 2 in the direction of rotationoftherunner so that a relatively high speed of rotation is attained. Thechannel between the rings 53 and 54 expands outwardly to accommodate thespread of the flowl against the bucket surfaces. The runner mayy alsobeprovided with an auxiliary cover 52 over the intake. The dischargefrom the runner is collected in the casing 55 and carried to the outlet56 connesting with the tailwater and the casing 55 is preferablyprovided with ya top 57 forming an airtight enclosure within which theVair pressure may be controlled by suitable connections.- In thismodiiication the lower edge of the nozzle 50 is adjustably carried bythe cylinder 58 actuated by the fluid pressure operated piston 60 guidedas shown while the guide vanes 49 are spaced an appreciable dis- Furtherobjects of the in` vention in providing simple and inexpensivey tancefrom therunner to form a transitionl space through which iiuid flows asa continuous 'circular and .solid j et to the runner.

In the modification shown in Fig. .3 the outward flow turbine vhasits'intake 48 provided with anadjustable top 51 forming anadjustableannular nozzle 5 0. 5.1 is supported by the rod 60 guided'inthe bearing 61 carried by the stays 62from the kwalls of the intakecasing, thelower'end of The top Y flector. Thek deiectoris moved bythebell I' cranks 70 engaging the pins 72 at opposite sides of thedeilector andthe bell cranks in turn are movedV byr thepiston rods 74moved by pistons in the fluid pressure cylinders 75. This deiiector d'operates to temporarily lrise and divert a portion oi the jet when thereis a sudden decrease in the load, rthe head 51 gradually movingk down toreduce the j et and the deilector l after its kiirst upward movementbeing lowered away from the jet.

Y The 'turbine of this invention provides a continuous radial jet and atthe same time enables the direction of the jet to be given any desiredinclinationor whirl aroundv the axis so as to increase thespeed of therunner.

a flat curvature and large angle to the radial direction so that arelatively small movement of the jet stream will cause a large rotativemovement of the runner and correspondingly high speed oi rotation. AttheV same time the torque on the runner may be maintained high comparedto impulse turbines of the tangential type for though the driving pres-Vsure on each bucket is small all of the buckets are continuously inoperation. For very high specific speeds the iiow into the runner may bedirected more nearly in the radial than the tangential directiom thaVis, at angles of 45O or more with the tangent. The control means for theflow comprise simple axially movable parts and all the surfaces of thejet forming and control parts are circular and may be easily turned toaccurate fit.

The guiding Y surfaces at the nozzle edges are steeply inclined to givesufficient contraction so that the jet does not attain its maximumvelocity until clear of the nozzle edges and diffusion of the jetisavoided.` A passage continuous around the circumference is providedbetween the discharge ends of the guide vanes and the nozzle orifice topermit the separate streams discharged between the vanes to cometogether in a continuous stream; and sufficient cont laction of thepassage is provided in the direction of iiow to insure the formation ofa solid stream, the outermost filaments of the jet continuing toapproach each other so as to overcome any tendencyof 'thej et to spreadout or diffuse. In the runner the ilow spreads out against the surfacesof the buckets or vanes and 1s surounded by air Y on the other threesides. The tendency of the discharge to entrap air and carry it out withthe water is utilized to produce a partial vacuum within the surroundingair-tightcas ing thus lowering the pressure against which the etdischarges and increasing the effective head on the turbine, byvutilizing' the fall from the runner to tailwater.

By directing the water into the runner in radial planes without faxialcomponents of iiow, the water may be given a high radial component ofmotion and a reduced tangential component, in order to produceacomparatively low torque and correspondingly high `speed of rotation ofthe runner, as has already been mentioned. This can be done withoutsubjecting the runner to a high axial thrust, since all of the `radialcomponents of the impulse of the entering water are balanced. Byavoiding axial components, com plexities are avoided in the flowvconditions and vane formation.

In both of the embodiments described, the water both enters and leavesin substantially radial planes7 and no axial thrust is produced. In allof the embodiment-s described there is no side thrust upon the runnerina direction normal to the axis such as exists in impulse turbinesofthe socalled tangential type in which the water is admitted at onlyone point in the periphery.

This application is a division of my.c.opending application Serial No.445,067, filed February l5, `1921. i

I claim: y

l. In an impulse turbine the combination with a runner of the free jetor impulse type, of an inlet passage'having a cylindrical oriticedirecting a continuous circular jet outward in a substantially radialplane against said runner, and means in said passage for imparting tosaid jettangential components of flow with respect to the axis of saidrunner said `means being spaced from said runner to form a transitionspace for effecting said continuous circular et.

2. In any impulse turbine the combination with means for Vforming aradially outward progressing continuous circular jet containingtangential components of motion, of a runner having a circular series ofbuckets continuously acted upon by said jet and means for Vvarying thethickness of said jet to control the speed of said runner. s

3. Ina hydraulic turbine a nozzle circularly symmetrical about an axisailaptcd to produce a free 'iet directed outward in a substantiallyradial plane and containing guiding means to give the et both radial andtangential components of flow with respect to said axis, said guidingmeans being spaced from said runner to form a transition space, and thewalls of said nozzle being'formed to direct the outermost streamelements couver gently toward each other to'preserve a continuouscircular body of fluid flowing from the nozzle through saidtransitionspace tothe runner entrance.

4. In animpulse turbine in the combination of a runner having vanesinclined to the radial and in the direction of rotationof the runner, ofa nozzle adapted to form a j et directed outward toward the runnerperiphery,

and means for guiding said jet against said runner with tangentialcomponents and in a direction more nearly radial than tangential andbeing spaced from saidv runner to form a transition space. y

5. In anV impulse turbine the combination with a vertical shaft runnerhaving a series of buckets suspended from a crown ring above, of etforming means within and spaced` from said ring of buckets to form atransition space and to direct the iiow with tangential components intothe inner entrance portions of said buckets. 6. In an impulse turbinethe combination with a vertical shaft runner having a series of bucketssuspended from a kcrown ring above, of jet forming means within andspaced from said ring of buckets to forma transition space and to directthe flow with tangential components into the inner entrance portions ofsaid buckets, the flow being dischargedV outwardly from the outerportions of said buckets.

7. In an impulse turbine the combination with a vertical shaft runnerhaving a series of buckets suspended from a crown ring above, of etforming means within and spaced from said ring of buckets to form atransition space and to direct the flow with tangential components intothe inner entrance'portions of said buckets, and means .for regulatingthe size of said jet. i

8. In an impulse.V turbine the combination with a vertical shaft runnerhaving a lseries of buckets carried by a crown ring, of jet formingmeans within and spaced from said ring of buckets to form al transitionspace and to direct the flow with tangential components into the innerentrance portions of said buckets, said buckets having vanes inclined tothe radial in the direction of rotation of the runner. .Y

9. In an impulse turbine the combination with a vertical shaft runnerhaving a series of buckets suspendedfroin ar crown ring abov, of jetforming means Within and spaced from said ring of buckets to form atransition space and to direct the HOW With tangential components intothe inner entrance portions of said buckets, and enclosing means adaptedto permit said runner to operate in air having a pressure less thanatmospheric.

10. In an impulse turbine the combination With a vertical shaft runnerhaving a series of buckets carried by a crown ring, of jet forming meansWithin and spaced from said ring of buckets to form a transition spaceand thereby direct an annular flow With tangential components into theinner entrance por tions of said buckets, said buckets having vanesinclined everywhere to the radial in the direction of rotation of therunner.

LEWIS FERRY MOODY.

